Total organic carbon (TOC)

Total organic carbon (TOC) is used as a measure of water quality. TOC in source water comes from decaying natural organic matter (NOM) as well as synthetic sources.  Humic acids, fulvic acids and urea are examples of NOM.  Detergents, pesticides, fertilizers, herbicides, and chlorinated organics may contribute to systhetic sources.   Higher levels of TOC suggest water quality impact.  Total organic carbon provides a medium for the formation of disinfection byproducts.  These byproducts include trihalomethanes (THMs) and haloacetic acids (HAAs).

Total organic carbon (TOC) has no health effects.  There is no drinking water standards for TOC, but if water with elevated TOC is disinfected with chlorine, disinfection byproducts may be generated.  Disinfection byproducts in excess of their MCLs may lead to adverse health effects, liver or kidney problems, or nervous system effects, and may lead to an increased risk of getting cancer.  See Bromate, Chlorite, and Total Trihalomethanes for more information.

Input units: 
Contaminant group: 
Action is optional 1: 

Total organic carbon levels were detected in your water sample. There is no health-based standard for total organic carbon. If you have concerns about the levels detected, please consult your physician.

Typical range in Ohio: 
2.0 - 2.4
Major sources in drinking water: 
Naturally present in the environment